Gerrit van detii



' UNITED STATES PATENT OFFICE.

GERRIT VAN DETI'I, OF NEYV YORK, N. Y.

MANTLE OR HOOD FOR INCANDESCENT GAS-LAMPS.

SPECIFICATION forming part of Letters Patent N 0. 574,862, dated January5, 1897'.

Application filed March 28, 1895- Serial No. 543,578. (No specimens.)

.To all whom it may concern:

Be it known that I, GERRIT VAN DETH, a subject of the Queen of Holland,residing at the city of New York, county and State of New York, haveinvented a certain new and useful Improvement in Mantles or Hoods forIncandescent Gas-Lamps, which is fully set forth in the followingspecification.

My invention relates to devices which are generally known as hoods,mantles, or gratings, which are adapted for use as illuminating devicesby bringing to a state of incandescence when submitted to the flame ofgas produced bya suitable gas-burner, such, for instance, as one of thewell-known B un sen type.

My invention will be fully understood by referring to the followingspecification, the essentially novel features being particularly pointedout in the claims at the end thereof.

The illuminating property of several species of refractory earths orinfusible materials when heated to incandescence is well known, and thisprinciple has been made use of in the construction of several types ofincandescent hoods or burners. My present invention is based upon thesame principle. The incandescent hood or mantle consists of a skeletonframe of the oXids, of well-known form, impregnated with certainrefractory earths or infusible materials and ammonium nitrate, ashereinafter mentioned. I impregnate a fabric of cotton with the saidmaterials by immersing it in a solution of the nitrates of suchmaterials, then drying, and then consuming or burning out thecombustible material by submitting to heat of sufficiently high degreeto accomplish this result.

My novel compound for the impregnation of a fabric or hood consists ofthe following materials, viz: first, thorium nitrate; second, ceriumnitrate; third, ammonium nitrate; fourth, lithium nitrate; fifth,zirconium nitrate; sixth, yttrium nitrate. The proportions of theseseveral elements employed in making the mixture are as follows, the saidproportions, as here given, being in weight: first, thorium nitrate,ninety-eight parts; second, cerium nitrate, 0.74 parts; third, ammoniumnitrate, 0.315 parts; fourth, lithium nitrate, 0.315 parts; fifth,zirconium nitrate, O. 315 parts; sixth, yttriumnitrate,0.315 parts.

The solution for use is obtained by dissolving these several salts inany liquid or liquids known as adapted and suitable for this purpose,the solution being preferably saturated.

The base for the incandescent hood or mantle is a fabric, cotton, forinstance, preferably in the form of a seamless cylinder, though thisspecific form is not absolutely essential. This fabric, woven orotherwise produced in the form desired, is dipped into or submitted to abath in the solution mentioned above and is there retained until itbecomes fully saturated with the said solution one minute. The saturatedfabric is then removed from the solution and submitted to a squeezing orpressing force, which may be obtained, for instance, by passing thefabric between compression-rollers of rubber or any other suitablematerial. The fabric after submission to this step in the process isnearly dry and is then completely dried by submission to heat of lowdegree, but sufficiently high to evaporate substantially all themoisture.

When substantially dry after the lastmentioned step in the process, thatportion of the fabric which in use will be the upper part of the hood ormantle is doubled upon itself, and an asbestos thread is stitchedthrough this doubled part and the diameter of the latter then reduced bydrawing the ends of the asbestos thread together and then tying them.The asbestos thread is then drawn diametrically through this reducedpart of the hood or mantle and fastened in any suitable way, and thehood or mantle is then submitted to the action of a flame on anysuitable burner- Bunsen, for instance-whereby the combustible mattercontained therein is entirely consumed or burned out. WVhen thus heatedto burn out or consume the combustible material, the nitrates of thethorium, cerium, lithium, zirconium, and yttrium with which the fabricis impregnated change to oxids, and in this form are non-combustible andremain so, retaining the shape of the article thus produced, which maybe described as a skeleton frame of an incandescent illuminant, which ifcarefully handled will remain effective in practical use upon a suitablegas-burner for at least one thousand hours.

The gas lamp or burner with which this incandescing hood or mantle maybe used is of any construction suitable for the purpose, such, forinstance, as aburner of the Bunsen type; but as the construction of thegas burner does not constitute a part of the present invention adescription thereof is not here necessary.

In the formula stated above specific proportions of the several elementsof the com position are given which I believe will produce the bestresult; but I do not wish to be understood as limitingmy invention tothe exact proportions named in specific minute details, for theseproportions may be varied slightly without losing the main features ofthe invention.

I have discovered that by combining the salt of a nitrate, such aslithium nitrate, with other well-known incandeseing materials, such asthose hercinbefore described, there results, when a hood has beentreated in the manner described and subjected to a heat sut'ficicnt torender it incandescent, oxid of lithium, and that such oxid of lithiumwhen combined with the other resultant oxids causes the hood to give avery much more et'fieient light than results from the combination of anyof the before-mentioned elements when combined without a lithium salt.

It is my belief that this result is attributable to the fusion of thelithium oxid, whereby the other oxids are caused by their combinedaction with the fused oxid to give increased incandesein g effects.Whether this theory be true or not I am not positive, but at the presenttime it appears to be the most plausible theory upon which to base thein creased efliciency which has been found by me to result from such acombination. I have made a number of comparative tests with well-knownforms of incandescin g hoods, embracing nitrates of the materialshereinbefore mentioned, and other hoods embracing the same materialscombined with lithium nitrate, and I have found that the combina- 4 tionof elements involving lithium nitrate produces a marked iIHDI'OVGIllOi]t in the illuminatin g capacity of a hood.

Having thus described my invention, what I claim to be new, and desireto secure by Letium nitrate, Zirconium nitrate, and yttrium nitrate, inproportions substantially as described.

"2. A compound for an incandescent light mantle, including a nitrate oflithium adapted to be converted into an oxid by heat, substantially asdescribed.

3. As an article of manufacture an incandescent mantle im 'iregnatedthroughout its body with a lithium salt, substantially as dcscribed.

4:. As an article of manufacture an incandescent mantle impregnatedthroughout its body with an oxid or hydroxid of lithium, in combinationwith one or more refractory earths.

As an article of manufacture a burned mantle, containing an oxid orhydroxid of lithium as a compound part among certain refractory earths,substantially as described.

(5. The described process of preparing an incandescent hood or mantlewhich consists in impregnating the hood with nitrates of thorium,cerium, ammonium, lithium, zirconium and yttrium in substantially theproportions named, then subjecting the hood to a low degree of heatsuflicient to evaporate the moisture and finally subjecting it to theaction of a flame until the combustible matter is entirely consumed orburned out.

GERRIT VAN DETII.

Witnesses:

EDW'ARI) J. lnEs'r, 'l. C. CRA FORD.

